Lead Fluxes Andreas Held, Caroline Leck, Ian Brooks, Barbara Brooks, Sarah Norris.

Lead Fluxes

Andreas Held, Caroline Leck, Ian Brooks, Barbara Brooks,

Sarah Norris

SOURCES

TRANSPORT DRY DEPOSITION

open sea sea-ice lead

TRANSFORMATION

surface albedo

cloud albedo

CCNscattering & absorption

WET DEPOSITION

Simplified Arctic Aerosol Life Cycle

Open Lead Flux System

1) Gill sonic anemometer

2) CLASP optical particle counter

(0.24 < Dp < 18.5 µm)

3) CPC 3760A condensation particle

counter (Dp > 11 nm)

4) LICOR 7500 CO2/H2O analyzer

5) MOXA dataloggerCLASP units

LiCOR 7500

sonicanemometer

Examine the capacity of the open leads to emit particles to the air by eddy covariance measurements:

fully battery operated (low power consumption)

located close to the ice edge ~2 m above the surface, near bubble camera site

Neutral Case

z/L=0z0=0.001 m, σv / u* = 2zm=1, 2, 3 m

wind

10 20 50 100 mPhoto: H.J. Zwally, NASA Goddard

Footprint Analysis of Open Lead Flux System

FSAM (Schmid, 1994)

Pu

mp

Sensing head

25 cm

• 16 channels - 0.24 to 18.5 m diameter• Flow rate 3 l/min – high sampling statistics allows 10 Hz temporal

resolution• Compact (25 x 8 x 6 cm) – allows collocation with sonic anemometer,

short inlet tube and low flow distortion, & installation in balloon instrument package and on buoy

CLASP Instrument

• Total particle number concentration for Dp > 11 nm

• Flow rate 1.5 l/min – good counting statistics

• 10 Hz sampling, but actual time response is slower

• Provides additional size bin from 10 nm to 240 nm in combination w/ CLASP

Condensation Particle Counter

Spray Sampler for Filter Collection and Electron Microscopy

Stockholm prototype:

• artificial bubble generation below water surface

• adjustable bubble diameter to generate film/jet droplets

• spray collection w/ filter sampler for off-line analysis

• spray collection on EM grid for electron microscopy

• free floating on water

• height adjustment of bubbler & sampler